Process of preparing vegetable fibers.



UNITED STATES BERTRAND S. SUMMERS,

PATENT OFFICE.

.OF CHICAGO, ILLINOIS.

PROCESS OF PREPARING VEGETABLE FIBERS.

SPECIFICATION forming part Of Letters Patilfi No. 650,917, dated June 5, 1900.

Application filed July 28, 1898. Renewed November 3, 1899. Serial No. 735,717. (No specimens.)

To all whom it may concern:

Be it known that I, BERTRAND S. SUMMERS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvementin Processes of Preparing Vegetable Fibers, of which the following is a full, clear, concise, and exact description.

My invention relates to a process for preparing vegetable fibers, being more particularly applicable to the preparation of flax fibers, although it is applicable to other fibers as well.

My object is to provide a process whereby the gum and cementing material which are present in the natural state may be elfectively and economically .removed to leave the fibers in a separated and refined condition.

The fibers to be prepared are in accordance with the present invention immersed in a solution containing a soluble salt of hydrofluoric acid and subjected to the chemical or solvent action thereof to thereby remove the gum and other cementing material. I have employed in practice sodium fiuorid and potassium fiuorid and have also used fluorids of tin and lead. lVhere commercial fiuorids are employed, I preferably add a small quantity of hydrofluoric acid to the solution to convert any carbonates or other salts into fluorids. The solution is in practice subjected to pressure, usually about one hundred pounds gage pressure, as the process is thereby greatly expedited and facilitated. The solution and the fibers to be degummed and prepared are placed in a vat or digesteradapted to be sealed in any manner, and by means of steam-coils or otherwise the solution is heated, usually to a temperature ranging from 300 to 335 Fahrenheit, the steam generated within the sealed vessel serving to subject the solution to the desired pressure.

In preparing flax I have employed the proportion of one hundred and thirty gram's of commercial sodium fluorid to thirteen liters of water, usually adding thirteen cubic centimeters of commercial hydrofluoric acid to the solution. The flax-stalks are immersed in the crude state and at a pressure of about one hundred pounds gage pressure and at a temperature of about 335 Fahrenheit. The

washing process with good effect.

process takes usually about thirty minutes. In the absence of the pressure above the atmosphere, however, the process takes from six to eight hours. The solution, besides removing the gum binding the fibers together, removes the outer skin and removes the cementing material between the fibers and the wood and makes the wood brittle. At the end of this operation the fibers are removed from the solution and washed'in water or an aqueous soap solution, distilled water being preferably employed, the water being usually heated under pressure to expedite the operation and to prevent violent ebullition, which would tend to entangle the fibers. I have, however,used ordinary hydrant-water for the If washed under pressure, a period of fifteen minutes will suffice, while if not under pressure the period should be practically doubled. After being washed the fibers are dried in any of the usual ways and then passed through breaking-rollers and scutched,after which the fibers are ready for carding and use in the textile arts.

'By the term chemical or solvent action as employed herein I contemplate any ac tion of a solution of a chemical or physical nature as distinguished from an electrochemical action.

Having described my invention, what I .claim as new, and desire to secure by Letters jecting the fibers to the chemical or solvent action of a solution containing a soluble salt of hydrofluoric acid and a small quantity of hydrofluoric acid sufficient to convert any subjecting the fibers to a washing-bath, sub stantially as described.

In witness whereof I have hereunto subscribed my name in the presence of two witnesses.

BERTRAND S. SUMMERS.

\Vitnesses:

II. R. KINGMAN, W. CLYDE JONES. 

